Abrading machine



Dec. 5, 1933. g 150M 1,937,771

ABRADING MACHINE Filed Jan. 13, 1930 2 Sheets-Sheet 1 EZ UcJZZE T- Carl L. J'Iw 1230724 -274Z M, C535- C. L. MA'TTISON ABRADING MACHINE Filed Jan. 13. 1930 2 Sheets-Sheet 2 ,lwerzm GarLJJ. JVQZT" 012/, 3

Patented Dec. 5, 1933 UNITED STATES PATENT OFFICE ABBADING MACHINE corporation of Illinois Application January 13, 1930. Serial No. 420,353

3 Claims.

My invention relates to abrading or polishing machines, and refers more particularly to that type in which an endless abrading or polishing belt is applied to the work to be treated by means 5 of a reciprocating shoe structure which bears upon one run of the traveling belt.

Machines of this type are disclosed in my prior Patents Nos. 1,4739% and 1,478,575, and application Serial No. 100,506, filed April 8, 1926, wherein an endless abrading belt traverses the work in slightly spaced relation thereto. The belt is adapted to be pressed onto the work by a reciprocating shoe pressing on the inner side of the lower run of the belt. In the machines shown in said patents, only one abrading belt is employed and, if it is necessary first to use a coarse and then a fine abrasive on the work, it is nece sary to stop the machine and change the belt. It is obvious that such a change requires time during which the machine is idle for productive purposes.

The general object of the present invention is to provide a machine of this type in which both coarse and fine abrading may be selectively accomplished without any loss of productive time due to changing from one form of abradlng to the other. More in detail, the object is to provide machine having a pair of belts having coarse and fine abrasive material respectively, and a reciprocatory pressure shoe structure which is shift able by the operator to exert pressure upon either belt.

Another object is to provide a pressure shoe structure comprising a pair of shoes, one for each belt, which shoes may be alternately brought into active position under the control of the operator.

A further object is to provide a machine having a reciprocating shoe structure of this character in which the shoes may selectively exert equal pressures on their respective belts for a given depression of the reciprocating structure, and in which each shoe exerts its pressure in a line directly perpendicular to the surface of the work.

Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings, in which:

Figure l is a front elevational View of a ma chine equipped with improvements embodying the features of the present invention.

Fig. 2 is a fragmentary and elevational view of the machine.

Fig. 3 is an enlarged front elevational view of the reciprocating shoe structure.

Fig. 4 is an enlarged end elevational view of the structure shown in Fig. 3.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein de- M scribe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

My improvement in the preferred form herein disclosed comprises in general a pair of abrasive belts. a power driven reciprocating structure having a pair of shoes for applying pressure to the belts respectively, and means operable while the machine is running for selectively bringing the shoes into active position whereby the operator may apply either belt to the work as desired without having to stop the machine.

The general arrangement of the machine being the same as that shown in the prior patents, referred to above, only a brief description thereof will be given here.

The machine comprises a pair of pedestals 10 upon which a table 11 for carrying the work A is mounted for movement forward and back andv with a vertical adjustment. Upon the top of the pedestals 10 is mounted a frame 12 which carries the various driving and controlling mechanisms. These include two oscillating pulleys 13 for reciprocating an endless steel tape 14, or the like, Two pairs of coaxial pulleys 15 and 16 are mounted on the ends of the frame 12 respectivcly, and over them pass a pair of endless abrasive belts l7 and 18, one of which has a coarse abrasive for roughing and the other a fine abrasive for finishing. A guide rail 20 is horizontaliy mounted between the opposite runs of the belts l7 and 18 and is supported for limited vertical movement by the arms 21. A handle 19 is provided for depressing the rail, by means of which pressure is applied to the belts through the reciprocating structure.

The reciprocating structure comprises a carriage 22 having a C-shape which surrounds the rail 20 and has rollers bearing thereon so that it is easily movable along the rail 20. A supporting member 23 is rigidly attached to the underside 105 of the carriage 22 and has an arm 24 extending rearwardiy. to which the reciprocating tape 14 is adjustably clamped as by screws. Thus, when the arm 24 is clamped to the tape 14, the carriage 22 will be reciprocated along the rail 20.

Below the supporting member 23 is mounted a member 25 by means of a horizontal pivot comprising screws 2? passing through the mid-point of the pivoted member 25 and threaded into the supporting member 23. On the respective ends of the pivoted member 25 are mounted a pair of shoes 26 which lie over the lower runs of the belts 17 and 18 respectively and are arranged to be selectively pressed downward, by pivoting the member 25, against the belts 1'7 and 18 for bringing the latter into active position relative to the work A.

The shoe structure and the means of support are substantially the same as are shown in the prior patents. The pivoted member 25 is provided with a pair of downwardly extending lugs 30 for each shoe, in which are threaded a pair of pointed screws 31 seated in a block 32. At right angles to the screws 31 is a similar pair of screws 33 seated in the block 32 and threaded in a pair of lugs 34 extending from the top of a plate 35. Springs 36 are interposed between the plate and the pivoted member 25 and are held in place by pins formed on the plate 35 and the pivoted member 25. Thus, the plate 35 is supported by the pivoted member 25 through a universal joint and is yieldingly held in a position parallel to the pivoted member 25 by the springs 36.

The plate 35 is provided on its under surface with a beveled groove 40 which slopes at a slight angle to the horizontal. The shoe 26 has a portion 41 fitting into the groove and is held rigidly in place by means of a bolt 42. When the pivoted member 25 is in a level, or inoperative, position both shoes 26 assume a slanting positnon, as shown in Figure 4, due to the slope of the groove 40. But, when one end of the pivoted member 25 is depressed, the angle of the slope of the groove 40 is sufficient to bring the lower surface of the shoe 26 into a horizontal position pressing against its belt. Each shoe 26 is constructed in substantially the same manner as is shown in the prior patents with anti-friction facing material secured to its lower face by means of a clamping mechanism 43.

As motioned above, means is provided for selectively bringing the shoes 26 into active position pressing against the belts 17 or 18. As illus- (rated in the drawings, the means provided is in the form of a pair of cams 44 and 45 which are rigidly mounted at opposite ends of a shaft 46 rotatably mounted in the supporting member 23. The cams 44 and 45 are positioned on opposite sides of the pivot 27 of the pivoted member 25 and strike against hardened surfaces 4'? formed on the upper face of the member 25. As shown in Fig. 3, the cams are oppositely mounted upon the shaft 46 so that turning the shaft 46 in one direction will cause one end of the pivoted member 25 to be depressed, while turning the shaft 46 in the other direction will cause the other end to be depressed. Each cam is provided with a rounded cam surface 48 and a flattened end surface 49, the latter serving to hold the cam in its depressing position when turned to the extremity of its movement. A hand lever 50 is rigidly mounted on the front end of the shaft 46 where it is accessible to the operator and may be readily moved to depress the shoes 26 either when the reciprocating structure is in motion or is still.

From the above description, it is evident that I have provided a machine of the type disclosed in my prior patents but which may selectively be employed for coarse or fine abrading and which may be shifted from one form of abrading to the other while the machine is running and without loss of productive time.

I claim as my invention:

1. In a machine of the character described, the combination of a pair of abrasive belts, a reciprocatory carriage, a member horizontally pivoted to said carriage, a pair of shoes supported by said pivoted member and arranged to be pressed against said belts respectively. cam means mounted upon said carriage and arranged to turn said pivoted members whereby said shoes may selectively exert pressure on said belts, and a hand lever for operating said cam means.

2. In a machine of the character described, the combination of a pair of parallel abrasive belts, a reciprocatory carriage, a member horizontally pivoted at its mid-point to said carriage, a pair of shoes pivotally supported on the ends of said pivoted member respectively and constructed to press on the belts respectively, a pair of cams rotatably mounted on said carriage and operable to bear on the ends of said pivoted member respectively to cause said shoes to against the belts, and a hand lever for rotating said cams whereby the belts may selectively be caused to press upon the work.

In a machine of the character described, the combination of a pair of abrasive belts, a reciprocatory carriage, a member pivoted to said carriage, a pair of shoes, a pair of resilient universal joints normally suspending the respective shoes from said pivoted member at an angle thereto, and means mounted on said carriage and arranged to turn said pivoted member whereby said shoes may selectively exert pressure on said belts. the angle at which each resilient universal joint normally suspends each shoe being equal to the angle through which the pivoted member is turned in order to exert an even pressure on each belt.

CARL LAWRENCE MATIISON. 

